High magnetic field-induced grain refinement of undercooled Inconel 718 superalloy

The undercooled solidification of the Inconel 718 superalloy under high magnetic field was performed for the first time at high undercoolings (∼ 200 °C). The results show that the high magnetic field can significantly refine the grains of the undercooled alloys, with the average grain size decreasing from 241 ± 92 μm at 0 T to about a third under high magnetic fields (3 T ∼ 9 T). Detailed EBSD analysis provides clear evidence that Icosahedral Short-Range Order (ISRO) enhanced nucleation occurs. The present work opens up a new way for grain refinement of alloys.